Contribution of large genomic rearrangements in BRCA1/2 genes and CHEK2 1100delC allele variant to the development of breast/ovarian cancer in Argentinian population

Purpose: Among women in Argentina, the most common cancer is breast cancer (BC) with 21,631 new cases and 6436 deaths per year. The ovarian cancer (OC) is fifteenth in frequency. The contribution of cancer-related large genomic rearrangements (LGRs) of the BRCA1/BRCA2 genes and the 1100delC allelic variant in the CHEK2 gene has not yet been widely studied in our population.

Methods: LGRs in the BRCA1/BRCA2 genes and the CHEK2 1100delC variant were analyzed using the MLPA technique in 85 unselected Argentinian BC/OC patients.

Results: A pathogenic genetic variant (PV) was found in eleven out of 85 (12,9%) patients, 10 were LGRs in the BRCA1 gene, 9 deletions and one duplication and one the CHEK2 1100delC. Large deletions of exons 1-2 and 15 in BRCA1 gene were recurrent anomalies in our series.

Conclusions: LGRs in the BRCA1 gene contributed significantly to the burden of PVs responsible for the development of BC and OC in our study population. On the other hand, the 1100delC variant in CHEK2 was observed at a very low frequency in our series formed mainly by the Spanish, Italian and Amerindian ethnic groups.